A micro-electro mechanical system (MEMS) often includes a micro structure, a micro sensor, a micro actuator, and corresponding processing circuits, etc. MEMS technology is a frontier high-tech subject that has been developed based on integration of various micro-processing techniques and applications of the latest achievements in modern information technology.
The development of MEMS technology has opened up a whole new technical field and a new industry. Fabricated by MEMS technology, micro sensors, micro actuators, micro component parts, micro mechanical optical devices, vacuum micro electronic devices, power electronic devices, etc., have very broad application prospects in aviation, aerospace, automotive, biomedical, environmental monitoring, military, and almost every single field that people may be able to practice.
Currently, the fabrication method for MEMS devices in the field of optics may include providing a substrate and forming a plurality of openings in the substrate by etching the substrate from the front side to the back side. The depth of the openings may be smaller than the thickness of the substrate. After forming the plurality of openings, the fabrication method may also include forming a photosensitive layer on the bottom and the sidewall surfaces of the openings. Further, the fabrication method also includes providing a carrier board and then bonding the substrate to the carrier board. Specifically, the front side of the substrate may be bonded to the carrier board so that the environment in the openings is nearly a vacuum. The fabrication method further includes forming a trench on the back side of the substrate by removing a portion of the substrate from the back side through etching. The trench exposes the portion of the photosensitive layer formed on the bottom surface of the openings.
However, for MEMS devices formed by such a current method, the sensing ability on external lights may still need to be improved while the performance may be poor. The disclosed fabrication method and MEMS device are directed to solve one or more problems set forth above and other problems in the art.